Gregor, you have done excellent work on this project. You took an empty shell and brought it to life. I think your frustration comes from thinking what you built isn't all you intended. That's something I'm very familiar with too.
Having never built this kit, I didn't realize how big the tower building is when built. Because of that I think my suggestion of a removable roof was not helpful at all. Perhaps a better solution to display all your work on the interior would have have been a removable wall or a seires of cut a ways.
i want to go off on a rant about the whole "kit assembler " vs "real modeler" business because it really makes my teeth hurt, but I leave it with this.
Gregor if you're "just" a kit assembler, then I'm proud to stand with you as another one.